Elucidating the Molecular Architecture of the FA-Core Complex Utilizing Biochemical Purification Approach.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1683-1683
Author(s):  
Abdullah M. Ali ◽  
Changhu Du ◽  
Thiyam R. Singh ◽  
Ruhikanta A. Meetei

Abstract FA is a rare, recessive disorder characterized by progressive bone marrow failure, developmental abnormalities, chromosome instability, cellular hypersensitivity to DNA cross-linking agents, and predisposition to cancer, mainly leukemias and squamous cell carcinomas of the head and neck. FA is genetically heterogeneous, represented by at least thirteen different complementation groups. The genes corresponding to groups A, B, C, D1 (BRCA2), D2, E, F, G, I, J, L, M and N have been cloned. The Fanconi proteins FANC -A, -B, -C, -E, -F, -G, -L, -M along with another newly discovered protein FAAP100 forms a core complex (CC) in the nucleus that is required for the monoubiquitination of two other Fanconi proteins FANCD2 and FANCI. In addition to their presence in nucleus, most of the Fanconi proteins are also found in the cytosol however their role in cytosol is not clear. Also, whether the FA-core complex proteins exist as a single complex or sub-complexes in the cytosol is not clear. The goals of this study are to develop a method of purification of FA core complex from nuclear and cytosol identify individual components of cytosolic and nuclear complex(s) of the FA proteins. We have established a two-step purification method using 6XHis and FLAG tags for the biochemical and functional characterization of the FA core complex proteins. In an attempt to isolate interacting partners of FANCC, FANCG, FANCL and FAAP100 proteins; we have established four different HeLa cell lines; HeLa-HF-FANCC, HeLa-HF-FANCG, HeLa-HF-FANCL and HeLa-HF-FAAP100, stably expressing HF-FANCC, HF-FANCG, HF-FANCL and HF-FAAP100 recombinant proteins respectively. Affinity purification was carried out to isolate the complexes from the cytosol and nuclear extracts prepared from stable cell lines. The polypeptides purified from the complexes were identified by mass spectrometry. The results suggest that, in addition to the existence of the FA-core complex containing FANC -A, -B, -C, -E, -F, -G, -L and 100, the FA proteins also exists as sub-complexes in the cytosol. FANCL was found to form a sub-complex with FANCB and FAAP100 in cytosol. Also FANCC, a predominantly cytosolic protein was found to form a sub-complex with FANCE in cytosol. We found several novel proteins that interact with FA proteins.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 989-989 ◽  
Author(s):  
Abdullah M. Ali ◽  
Thiyam R. Singh ◽  
Ruhikanta A. Meetei

Abstract Fanconi Anemia (FA) is an autosomal recessive and X-linked disorder characterized by congenital abnormalities, progressive bone marrow failure, and a high incidence of hematological (acute leukemia) and non-hematological malignancies (squamous cell carcinomas of the head and neck or gynecologic system). FA is genetically heterogeneous disease and to date 12 complementation groups are known of which 11 gene products have been identified (FANC- A, B, C, D1, D2, E, F, G, J, L, M). Eight of the FA gene products, FANCA, FANCB, FANC, FANCE, FANCF, FANCG, FANCL and FANCM form a multiprotein FA core complex. This complex is required for the monoubiquitination of FANCD2 upon DNA damage by various genotoxic agents. The other two FA proteins; FANCD1/BRCA2 and FANCJ are believed to act “downstream” of FANCD2. In order to understand the role of FA proteins in DNA repair pathway it is necessary to find all the FA genes and their interacting partners. We have established a two-step purification method using 6XHis and FLAG tags for the biochemical and functional characterization of the FA core complex proteins. In an attempt to isolate interacting partners of FANCM and FANCL proteins; we have established two different HeLa cell lines; HeLa-HF-FANCM and HeLa-HF-FANCL, stably expressing HF-FANCM and HF-FANCL recombinant proteins respectively. Two step affinity purification was carried out to isolate the complexes from the extracts prepared from stable cell lines. Two polypeptides, namely, FAAP16 and FAAP100 were identified by mass-spectrometry as major interacting partners of FANCM and FANCL respectively. The interaction of FAAP16 and FAAP100 with other FA core complex proteins was confirmed by reciprocal affinity purification coupled mass-spectrometry using HeLa cells stably expressing HF-FAAP16 and HF-FAAP100 proteins. Furthermore, suppression of FAAP16 and FAAP100 in HeLa cells using siRNA resulted in a reduced MMC-induced FANCD2 monoubiquitination. Studies are being carried out to understand the precise role of these proteins in the FA core complex. These data suggest additional proteins interact with FA core complex members and demonstrate the utility of the purification method in delineating interacting proteins involved in FA.


Blood ◽  
2006 ◽  
Vol 108 (6) ◽  
pp. 2072-2080 ◽  
Author(s):  
Annette L. Medhurst ◽  
El Houari Laghmani ◽  
Jurgen Steltenpool ◽  
Miriam Ferrer ◽  
Chantal Fontaine ◽  
...  

AbstractFanconi anemia (FA) is a genomic instability disorder, clinically characterized by congenital abnormalities, progressive bone marrow failure, and predisposition to malignancy. Cells derived from patients with FA display a marked sensitivity to DNA cross-linking agents, such as mitomycin C (MMC). This observation has led to the hypothesis that the proteins defective in FA are involved in the sensing or repair of interstrand cross-link lesions of the DNA. A nuclear complex consisting of a majority of the FA proteins plays a crucial role in this process and is required for the monoubiquitination of a downstream target, FANCD2. Two new FA genes, FANCB and FANCL, have recently been identified, and their discovery has allowed a more detailed study into the molecular architecture of the FA pathway. We demonstrate a direct interaction between FANCB and FANCL and that a complex of these proteins binds FANCA. The interaction between FANCA and FANCL is dependent on FANCB, FANCG, and FANCM, but independent of FANCC, FANCE, and FANCF. These findings provide a framework for the protein interactions that occur “upstream” in the FA pathway and suggest that besides the FA core complex different subcomplexes exist that may have specific functions other than the monoubiquitination of FANCD2.


Blood ◽  
2004 ◽  
Vol 103 (7) ◽  
pp. 2498-2503 ◽  
Author(s):  
Marieke Levitus ◽  
Martin A. Rooimans ◽  
Jûrgen Steltenpool ◽  
Nicolle F. C. Cool ◽  
Anneke B. Oostra ◽  
...  

Abstract Fanconi anemia (FA) is an autosomal recessive syndrome featuring diverse symptoms including progressive bone marrow failure and early occurrence of acute myeloid leukemia. Nine genetic subtypes have been described for FA (A, B, C, D1, D2, E, F, G, and L), all of which have been connected to distinct disease genes, except B. Here we report on 8 unrelated FA patients who were excluded from the known subtypes on the basis of phenotypic correction or genetic data. Four of these cell lines failed to complement each other in somatic cell hybrids and therefore represent a new group, termed FA-I. The remaining cell lines complemented group FA-I but did not complement each other, thus representing a second new group, FA-J. Both FA-I and -J cell lines were capable of forming an FA multiprotein core complex. This complex is required for activation of the FANCD2 protein by mono-ubiquitination, a key downstream event in the FA pathway. In FA-I cells FANCD2 was not mono-ubiquitinated, indicating a defect upstream in the FA pathway, whereas in FA-J cells FANCD2 was mono-ubiquitinated, indicating a downstream defect. Our results suggest that the FA pathway of genome stabilization may be controlled by at least 11 different genes, including FANCI and FANCJ.


1990 ◽  
Vol 63 (03) ◽  
pp. 439-444 ◽  
Author(s):  
C Kuyas ◽  
A Haeberli ◽  
P Walder ◽  
P W Straub

SummaryWith an immobilized synthetic pentapeptide GlyProArgProLys comprising the N-terminal sequence GlyProArg of the α-chain of fibrin, a new affinity method for the quantitative isolation of fibrinogen out of anticoagulated plasma was developed. The method proved to be superior to all known isolation methods in respect to ease of use and yield, since fibrinogen could be isolated in one step out of plasma with a recovery of more than 95% when compared to the immunologically measurable amounts of fibrinogen. Moreover the amounts of contaminating proteins such as fibronectin, factor XIII or plasminogen were negligible and the purity of the isolated fibrinogen was higher than 95% as measured by polyacrylamide gel electrophoresis. The clottability was 90% and more. Another advantage of this affinity purification method is the possibility to isolate fibrinogen quantitatively out of small plasma samples (<5 ml). Further, abnormal fibrinogen molecules, provided their complementary binding site for GlyProArg is preserved, may also be quantitatively isolated independent of any solubility differences as compared to normal fibrinogen. In addition fibrin(ogcn) fragments originating from plasmic digestion can be separated on the basis of their affinity to GlyProArg. The described affinity gel can be used more than 50 times without any loss of capacity.


2019 ◽  
Vol 7 (4) ◽  
pp. 91-96
Author(s):  
Isra'a Al-sobhi ◽  
◽  
Rawan Al-Ghabban ◽  
Soad Shaker Ali ◽  
Jehan Al-Amri ◽  
...  

Author(s):  
Junjian Li ◽  
Lianbao Ye ◽  
Yuanyuan Wang ◽  
Ying Liu ◽  
Xiaobao Jin ◽  
...  

Background: Spirocyclic indoline compounds widely exist in numerous natural products with good biological activities and some drug molecules in many aspects. In recent years, it has attracted extensive attention as potent anti-tumor agents in the fields of pharmacology and chemistry. Objective: In this study, we focused on designing and synthesizing a set of novel 1'-H-spiro[indole-3,4'-piperidine] derivatives, which were evaluated by preliminary bioactivity experiment in vitro and molecular docking. Method: The key intermediate 1'-methylspiro[indoline-3,4'-piperidine] (B4) reacted with benzenesulfonyl chloride with different substituents under alkaline condition to obtain its sulfonyl derivatives (B5-B10). We evaluated their antiproliferative activities against A549, BEL-7402 and HeLa cells by MTT assay. We performed the CDOCKER module in Discovery Studio 2.5.5 software for molecular modeling of compound B5, and investigated the binding of compound B5 with the target proteins from PDB database. Results: The results indicated that compounds B4-B10 exhibited good antiproliferative activities against the above three types of cells, in which compound B5 with chloride atom as electron-withdrawing substituent on a phenyl ring showed the highest potency against BEL-7402 cells (IC50=30.03±0.43 μg/mL). By binging of the prominent bioactive compound B5 to CDK, c-Met, EGFR protein crystals, The binding energy of B5 with these three types receptors are -44.3583 kcal/mol, - 38.3292 kcal/mol, -33.3653 kcal/mol respectively. Conclusion: Six 1'-methylspiro[indoline-3,4'-piperidine] derivatives were synthesized and evaluated against BEL-7402, A- 549, HeLa cell lines. Compound B5 showed significant inhibition on BEL-7402 cell lines. Molecular docking revealed that B5 showed good affinity by the good fitting between B5 and these three targets with amino acid residues in active sites which encourage us to conduct further evaluation such as the kinase experiment.


Author(s):  
Chen Shi ◽  
Yue-Ling Peng ◽  
Juan He ◽  
Zheng-Hui Li ◽  
Ji-Kai Liu ◽  
...  

AbstractTwo undescribed Tricholoma triterpenoids, namely tricholopardins C (1) and D (2), were isolated from the wild mushroom Tricholoma pardinum. Their structures with absolute configurations were elucidated by spectroscopic methods, as well as the single crystal X-ray diffraction. Compounds 1 and 2 were further obtained by chemical conversions from the known analogues. Compound 1 showed significant cytotoxicity to MCF-7 and Hela cell lines with IC50 values of 4.7 μM and 9.7 μM, respectively. Its mechanism of inducing MCF-7 cell apoptosis was studied briefly. Graphical Abstract


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